Injection engine



Aug. 16, 1932. J. D. HAY

INJECTION ENGINE Filed Sept. 50

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INVENTOR JOHN D. HAY BY ATTORNEY charge of fuel, and

compression, of the enfrlne speed, complete va Patented Aug. 16, 1932 UNITED STATES PATENT oFFlcE JOHN D. HAY, 0F SOUTH BEND, INDIANA, ASSIGNOB, BY MESNE ASSIGNMENTS, T0

l BENDIX AVIATION CORPORATION, A CORPORATION OF DELAWARE INJEc'rroN ENGINE Application led September 30, 1925. Serial No. 59,596.

This invention relates to injection engines, and its principal object is to inject the fuel in the form of a hot, diluted, carbureted mixture or vapor, instead of as a liquid or spray. Preferably the fuel is vaporized in hot exhaust gas from the engine, which is inert and therefore permits the vapor to be heated far above its temperature ofignition, and also permits it'to be injected by being compressed more highly than the air in the engine cyhnder.

In on'edesirable arrangement, the gas 1s sucked across a fuel passage, taking up a is then compressed and injected.' In order to secure adequate compression of the fuel charge without an extremely small com ression space above the pump piston, I pre er to add a furthercharge of gas unmixed with fuel, and des'cr1bed as hot exhaust gas from the engine cylinder. This dilutes the fuel mixture, facilitating the vaporization of the fuel and at the same time giving a greater volume to compress, without the disadvantage of the excesslvely fine metering-of the fuel which would be necessary if all the gas crossed the fuel passage in entering the pump cylinder. y

The new method of operation is especlally well adapted for small high-speed engines, in which the preparation of the fuel is eX- tremely important, the operation of such engines on the solid-injection Diesel principle, or with liquid fuel injected asa spray, having proved impossible up to the present time. Moreover, ordinary fuel-preparation methods are inadequate, owing to the eX- ,treme rapidity is gone through,-there being only a minute fraction of a second available for heating each charge. As the heat in the exhaust-gas part of the charge, and the heat added by are substantially independent orization of the fuel at all speeds is insure the temerature of the fuel charges in practice being above the ignitiontemperatureat the time of injection, so that complete combustion in the engine is insured.-

These and other objects and features ofl the invention, including various novel comwith which the engine cycle binations of parts and desirable particular constructions, will be apparent from the following description of one illustrative embodiment shown in the accompanying drawing, in which The figure is a section axially of the engine cylinder through the entire engine.

While the invention isn applicable to various types of engines, I have illustrated a two cycle engine including a cylinder 10, which may be provided with a water-jacket 12, and a piston 14, the cylinder and piston being arranged to provide a suitable combustion chamber 16. A relief valve 18 may be provided in the cylinder head 20, for use in starting. .The air charge is compressed in the crank case 22, and flows through a passage 24to the intake ort, not shown, which is uncovered when piston 14 is 1at the bottom of itsstroke, at which time there is also open an exhaust port (not shown) communicating with an exhaust conduit 26. Except as further described below, these parts or their equivalents may be of any desired construction. f

Fuel is supplied Vfrom any suitable source 28, through a conduit 30 to a passage or nogzle 32 controlled by ai manually-adjustable needle valve 34. Nozzle 32 opens into a passage 36 in a lfuel-valve assembly block 38 held by aV clamp rin 40 threaded in the cylinder head 20. Bloc 38 is formed with a pump cylinder 42 having a pump piston 44, and passage 36 opens into the cylinder a short distance above the position of the piston att-he lower end of its'stroke. Piston 44 is held from turning by a key 46, and has a cam roller 48 held bya sprin 50 against a cam 52 on the crankshaft 54. f desired, the fuel. in -source 28 may be under pressure. I prefer, however, to. provide a suitable check valve in the end of conduit 30, the fuel being'under atmospheric pressure only, so that conduit 30 an valve passage 34 arel jconstantly filled with fuel by the suction from piston 44 which thus. acts as a fuel-feeding pump for' the liquid fuel as well as for the vaporized fuel ,zgie 32, taking up a charge of fuel and time piston substantially at the bottom of its stroke,I

pump piston 44 uncovers a passage 58 opening through the' wall of block 38 the combustion chamber 16. This takes place before piston 14 uncovers its exhaust and air-v intake ports, or so soon thereafter that there is a substantial pressure in the engine cylinder, and consequentl hot exhaust gases from the engine cylinder yll the pump cylinder 42. Passage 58 .is almost immediately shut off, and passage 36 is shut 0E before the pressure V1n the pump cylinder builds up enough to cause back pressure on the valve 34 or on the fuel line.

Pump piston 44 now rises, the heat of compression added to the heat already in the exaust gases completely vaporizing the fuel charge. At the upper end passage in the pump piston registerswith passage 58, and the vapoiized mixture of exhaust as and fuel, at a tem erature considerably a ove the ignition oint of the fuel', is injected by virtue of its` igher pressure into combustion'chamber 16, in which piston 14 has compressed a chargeI of air, which air has been heated by the compression above the ignition point of the fuel.

The upper end of the pump cylinder 42 is A closed by a plug 62 held by a setscrew 64 in a yoke 66, and may be adjusted by shims or gliliskets 68 to vary the compression of the fuel c arge.

It will .be observed that when the engine is iirst started, on the iirst cycle the conduit 56 will supply cold air gas to the pump cylinder. However, the compression is so great that the fuel will be ignited on the compression'stroke of the pump piston 44, a small part of it burning and aiding the heat `.of compression in vaporizing the remainder of the fuel. Thus from the very first cycle, fully-vaporized highly-heated fuel charges are injected into the engine cylinder, and there is no need of complicated torches and other auxiliary heatersin starting.

While one particular enginehas been described in detail, it is net my intention to limit the scope of the invention by that description, lor otherwise than the appended claims.

l I c aim:

directly into suction stroke, an intake passa e of its stroke, a

land the gas from the chamber at the end of the instead of hot exhaust t passage opening into the intak by the terms of,

1Q An engine of the injection type comprising, in combination, an engine cylinder andipiston. with a combustion chamber above the piston, an adjacent pump cylinder and piston, a passage from the pump cylinder opening into the combustion chamber and uncoveredby the pump piston at the end of its suction stroke, an intake passage opening into the pump cylinder above the first passave, and a fuel passage openin into the inta e passage in such a manner t at gas rush. ing through the intake passage on the suction stroke ofthe pumpjpiston will take up fuel from the fuel passage, the pump cylinder and piston' being arranged to compress the fuel and the gas from the intake passage and thev gas received froml the combustion chamber at the end of the suction stroke and inject the compressed mixturefinto the combustion chamber at the end of the compression stroke of the pump piston.

prising, in combination, an engine cylinder and piston with a combustion chamber above the'piston, an adjacent piston, a passage from the pump cylinder opening into the combustion chamber and uncovered by the pump piston at the end of its opening into the pump cylinder above the rst passage, a el passage opening into the intake passage in such a manner that gas rushing through the intake passage on the suction strokeV of the pump piston will take u fuel from the fue passage, and an adjustab 'e valve controlling the fuel passage, the pump cylinder and piston being arranged to compress the fuel intake passa e and the gas received from the combustion c amber at the end of the suction stroke and inject the compressed mixture into the combustion compression stroke of the pump piston. Y 3. An en ine of the injection type comprising, in com ination, an en e cylinderand piston with a combustion czilmber above the piston, an adjacent ump cylinder and pison, a passage from t e pump cylinder opening into the combustion chamber and uncovered by the pump piston at the end of its suction stroke, an intake 'passage opening into the pump cylinder above the first passage but being uncovered near the end of the suction stroke of the pump piston, so that a considerable suction will exist in the pump cylinder when the intake passage is uncovered, thus giving a sudden inrush of gas through the intake passage, and a fuel e l passage in such a manner that said sudden inrush of gas will suck fuel from the fuel passage, the pump cylinder immediately thereafter being lled with gases from the combustion chamber as the first passage is uncovered, andthe pump lpiston being arranged to compress the mixed gases and inject them into the combustion chamber.

4. An injection `engine having an engine cylinder and piston arranged to' compress air 6 unmixed with fuel, and comprising in combination therewith, a pump cylinder communicating with the engine cylinder through two separate passageways to receive exhaust gases therefrom and to deliver a charge there- 10 into through one-of said passageways, a pump piston operable within the pump cylinder to uncover said passageways successively on its suction stroke to admit exhaust gases through both of them from the engine cylin- 15 der, means for delivering fuel' into the ump cylinder to mix with the exhaust gases t erein, said pump piston adapted to compress said mixture and eject it into lthe engine'cylinder. 2Q In testimony whereof, I have hereunto signed m name.

y J OBIN D. HAY. 

